We ALWAYS take the LiPo battery out to charge it.  There's always a risk for fire with a LiPo and it's not worth risking the airplane ever.  If you are speaking of the connector to the 2S lipo connection, you'll use same connector that's on the regulator as that is what the battery plugs in to.  It's usually a Futaba or JR type connector.  They come with a connector for the charger and it'll charge through that connector.


I'd pay attention to how much you put back into the pack after 3 or 4 flights.  Divide the number of mAh that you put back in by the number of flights that you put on that pack to get an average of the amount of mAh that you use per flight.  Don't drop below 20% capacity.  On the 730 pack, that means never put more than 584 mAh back in.

Always, always check your RX pack before each flight regardless.  I lost a 2S Lipo out of the clear blue.  One day it was fine, the next it was junk.  I caught it because I charged the pack the night before (of course at a competition) and everything was fine.  I checked the pack before putting in the first flight and the voltage had dropped considerably.  Turned out, a cell had started to go bad.